1. Field of the Invention
The present invention relates to medical devices, and, in particular, to a retractor for harvesting a blood vessel, which, in turn, is used in connection with an ongoing or subsequent surgical procedure. More particularly, the present invention provides such a retractor that is capable of defining and illuminating a subcutaneous working space to ameliorate accessibility to, and to facilitate visualization and harvesting of one or more blood vessels (e.g., radial artery, basilic vein) for grafting/transplantation in connection with a surgical procedure (e.g., coronary bypass surgery).
2. Description of Related Art
In certain surgical procedures, it is necessary to remove a portion (or even the entirety) of a patient""s blood vessel for use in another, often remotely located part of that, or a different patient""s body. For example, it is known to remove/excise some or all of a patient""s radial artery, saphenous vein, cephalic vein, basilic vein or mammary artery for transplantation in connection with a coronary bypass surgical procedure. Once transplanted, the removed section (or entirety) of the vein/artery functions as a graft that replaces both the coronary arteries, which, as a result of aging and/or disease, have become blocked by plaque deposits, stenosis, or cholesterol, thus severely inhibiting their ability to supply life-sustaining blood to the patient""s heart.
In some instances, these blockages can be treated with angioplasty, atherectomy or stent placement, and, therefore, coronary bypass surgery is not warranted. Quite often, however, a coronary bypass is required because these treatment methods are either contraindicated, or have proven incapable of removing blockages from coronary arteries.
According to current coronary bypass surgery techniques, a blood vessel is harvested from elsewhere within a patient""s body and grafted into a locus between the patient""s aorta and the coronary artery beyond the point of blockage. It is preferred to use a blood vessel taken from the patient undergoing bypass surgery, since he/she is a ready source of suitable vessels that will not be rejected by his/her own body after transplantation.
It has been found that each of a patient""s radial or mammary artery, or saphenous, cephalic or basilic vein has functional and structural characteristics (e.g., diameter) resembling those of the coronary arteries, thus rendering any of these vessels potential candidates for grafting.
Among these vessels, however, the radial artery and the saphenous vein are often favored for transplantation in connection with coronary bypass surgery, likely due to the comparative ease of their harvesting and/or the comparative lack of complications (especially post-operative) associated with their harvesting and/or their subsequent transplantation.
Harvesting the saphenous vein entails making an incision in a patient""s leg, and then pulling away layers of fatty tissue to reveal the saphenous vein, which is then carefully removed.
Until recently, the incision that was made to access the saphenous vein was quite longxe2x80x94spanning a patient""s groin to at least his/her knee, and often to his/her ankle. Making this xe2x80x9cfillet-likexe2x80x9d incision inherently presents a serious risk of injury to the medial lymph bundle and/or to nerves located within the leg, as well as a realistic risk of infection to the incision site.
Moreover, the healing process associated with this long, xe2x80x9cfillet-likexe2x80x9d incision is protracted (often more prolonged than the incision(s) to the patient""s chest in furtherance of the coronary bypass) and very painful, especially if the patient has circulation problems in his/her extremities. Ultimately, in fact, the incision often does not heal properly, thus requiring medical attention and/or invasive procedures (e.g., corrective surgery).
As indicated in U.S. Pat. No. 6,193,651 to DeFonzo, U.S. Pat. No. 6,228,025 to Hipps et al, and U.S. Pat. No. 6,322,499 to Evans et al., however, techniques now exist that allow the saphenous vein to be harvested by making several (usually either 2 or 3) smaller incisions on the proximal thigh, at the level of the knee joint, and, optionally, the inner malleolus.
In accordance with these techniques, a retractor is inserted into each of these incisions to define, access and illuminate the subcutaneous space. The retractor is used to form a skin bridge to allow for retraction of the fatty tissue surrounding the saphenous vein, which is then harvested.
Unfortunately, despite this advancement, many patients are not ideal candidates for saphenous vein harvesting by virtue of having an unacceptably high risk of minor to extensive complications associated with even these smaller leg incisions. Such patients include the elderly, the obese, diabetics, those who have developed extensive varicose veins in their legs, those who have fragile veins in their legs due to taking or having previously taken certain medications, and those whose saphenous vein is in a position that does not readily lend itself to harvesting.
These same patients, however, often are ideal candidates for other vessel harvesting options, such as radial artery harvesting, in which the radial artery is harvested from a patient""s arm (usually his/her non-dominant arm). The radial artery is one of two arteriesxe2x80x94the ulnar artery is the otherxe2x80x94in a patient""s forearm. Both these arteries stem from the brachial artery (the radial artery being the true continuation of the brachial artery) and, together, form a network of vessels, which supply blood to the wrist and hands, and which rejoin to form the palmar arch at the palm of the hand.
Radial artery harvesting is contraindicated in only a few classes of patients, such as those who have carpal tunnel syndrome, Raynaud""s syndrome, and those who have severe kidney disease or poor blood circulation to their fingers.
Harvesting the radial artery for transplantation/grafting in connection with coronary bypass surgery historically involved making a continuous, xe2x80x9cfillet-likexe2x80x9d incision from approximately two inches below (i.e., toward the hand) the patient""s elbow at the antecubital fossa to about one inch above (i.e., toward the elbow) the patient""s wrist. The length of such an incision was reported, on average, to be about 23 cm (i.e., about 9 inches). A. Uchida et al., Endoscopic Harvesting of Radial Artery Graft for Coronary Artery Bypass, Ann. Plast. Surg. 1998;41:459-463).
Just as making a xe2x80x9cfillet-likexe2x80x9d incision causes significant risks in the context of saphenous vein harvesting, making an approximately 23 cm (i.e., 9 inch) continuous cut into a patient""s arm to harvest the radial artery also presents serious risks, such as severing the delicate superficial radiac and/or lateral antebrachial cutaneous nerves.
In an effort to avoid these risks, it has been proposed (and is currently practiced) to instead make two, transverse, 2-3 cm in length incisionsxe2x80x94one at the patient""s wrist, and the another 4 cm from the patient""s antecubital fossa (see, e.g., Y. Terada et al., Endoscopic Harvesting of the Radial Artery as a Coronary Artery Bypass, Ann. Thorac. Surg. 1998;66:2123-4, and A. Uchida et al., Endoscopic Harvesting of Radial Artery Graft for Coronary Artery Bypass, Ann. Plast. Surg. 1998;41:459-463). Alternate loci for these two, tranverse incisions have also been proposed/practiced, including at 4 cm from the patient""s wrist, and at the middle region of the patient""s forearm (see Z. Galajda et al., Minimally Invasive Harvesting of the Radial Artery as a Coronary Atery Bypass Graft, Ann. Thorac. Surg. 2001;72:291-3).
Although specific radial artery harvesting techniques may differ with respect to equipment used and/or approach taken, they generally entail (once the two transverse cuts are made) inserting a retractor within each of these incisions to lift the skin and tissue (i.e., the deep fascia) located directly beneath the skin, thus forming several skin bridges between the incisions, and defining subcutaneous space beneath the skin bridges.
Generally, any remaining deep fascia tissue is then transected to reveal the bracioradialis and flexor carpi muscles, which are pushed aside to expose the neurovascular fascia, which are transected to reveal the radial artery within loose areolar tissue. The areolar tissue is then displaced to allow the radial artery to be harvested (e.g., by hand, with one or more tools)
Regardless of the size and placement of the incisions that are made within the patient""s arm, most radial artery harvesting techniques (including the Terada and Uchida techniques) necessarily rely upon the use of several instruments. Among these, generally, is an endoscopic apparatus, which provides visualization of the subcutaneous surgical field and, optionally, provides a lumen, through which tools may be introduced during the harvesting procedure, and/or through which the excised radial artery (or other tissue) may be withdrawn.
There are several notable drawbacks associated with using endoscopic technology for visualization of the subcutaneous space in connection with radial artery harvesting. First, the endoscope (or the display unit that depicts its image) provides a distorted visual perspective, which is a poor substitute for actual visualization of the surgical field by the naked eye. Second, compounding the first drawback, use of an endoscope provides for visualization of only a small portion of the subcutaneous space, namely, the area that is immediately in front of the endoscope. Third, illumination within the subcutaneous space created by this type of endoscope is also limited to the light emitted directly at the distal portion of the endoscope.
Because of these disadvantages, there is a significant learning curve to safely and efficiently practice this radial artery harvesting procedure.
Other drawbacks also are caused when attempting to use conventional equipment in connection with the skin bridging radial artery harvesting procedure. For example, because the skin bridges between the transverse incisions are quite long, it is difficult to sufficiently illuminate the subcutaneous space, especially when conventional, non-illuminated retractors are implemented/utilized.
Moreover, the area from which certain vessels are harvested may have smaller, narrower dimensions than the most other bodily areas within which vessels to be harvested are located. For example, a patient""s arm (in which both the radial artery and the basilic vein are located) is comparatively narrower than his/her leg, in which the saphenous vein is located. As such, the subcutaneous space within a patient""s arm is likely comparatively more crowded with instruments during the harvesting process, thus complicating the process and further prolonging the learning curve for safely and efficiently practicing radial artery harvesting.
Therefore, a need exists for a procedure that overcomes the aforementioned visualization- and illumination-related drawbacks, as well as the spatial limitations that individually and collectively plague conventional radial artery harvesting techniques and prolong the learning curve required for medical personnel to safely, yet expeditiously practice such techniques.
The present invention provides a surgical retractor that meets this, and other needs. As shown in the drawings, the present invention provides a retractor for defining, accessing and illuminating a subcutaneous working space near a blood vessel (e.g., the radial artery, the basilic vein) located within a patient""s arm in order to facilitate safe, reliable and expeditious harvesting of the vessel.
In an exemplary procedure for harvesting a patient""s radial artery, two small transverse (i.e., 2-3 cm) incisions are made in a patient""s non-dominant arm. The incisions are made either at the patient""s wrist and 4 cm from the patient""s antecubital fossa, or at 4 cm from the patient""s wrist and at the middle region of the patient""s forearm.
The surgical retractor of the present invention is inserted underneath the skin at one of the incision sites, and is used to lift a skin bridge and, preferably, some layers of the deep fascia as well. This lifting action defines a subcutaneous space, which is illuminated by the retractor to allow for visualization of the tissue and muscle located therein.
The retractor is retained in place via, for example, an external retention device attached to both the retractor and to a structure (e.g., the table on which the patient lies), thus allowing for the defined subcutaneous space to be maintained and illuminated. This, in turn, allows medical personnel use of its/their hands to locate and dissect any remaining deep fascia, thus exposing muscle (e.g., the bracioradialis and flexor carpi).
The muscle is moved (e.g., by hand or, preferably, with an instrument) to reveal neurovascular fascia, which is dissected to reveal the radial artery within loose areolar tissue. This tissue is then displaced (e.g., with an instrument or, preferably, by hand) to reveal the radial artery, which is then harvested according to techniques known to the ordinarily skilled artisan.
The illuminated retractor of the present invention provides a large, well-illuminated surgical field, which preferably extends the substantial length of the retractor within the subcutaneous space created by the retractor, and which, consequently, allows for illumination and improved visualization of the tissue and muscle that is located within the subcutaneous space, and that surrounds the radial artery. This, in turn, facilitates the harvesting procedure, and limits the risk of harming the delicate superficial radiac and/or lateral antebrachial cutaneous nerves.
The illuminated surgical retractor preferably has a handle member, a first elongate section and a second elongate section. The handle member is contoured to be gripped by medical personnel, and, in a preferred aspect of the invention, is pivotally connected to the first elongate section at the distal end portion of the first elongate section to permit one-handed use of the retractor by medical personnel.
Unless indicated otherwise, the term xe2x80x9cmedical personnel,xe2x80x9d as used herein, is intended to refer to a single individual that has a role in connection with a surgical procedure. The specific medical personnel who performs a given task in connection with the procedure described herewithin is determined based on the particular task, the level of training required to perform the task, and the availability of other medical personnel.
The handle member permits the retractor to be lifted at any desired angle with respect to the axis of the vessel (e.g., the radial artery). Application of a pulling force to the handle member results in a corresponding pulling or retraction force being applied to the skin and/or subcutaneous tissue via the first elongate section.
In an exemplary aspect of the invention, an elongated rod portion extends from the handle member. The rod portion allows the retractor to be maneuvered into a desired position by medical personnel and then fixed in this position by clamping or grasping the retractor with the available operating table retention mechanism(s).
The first elongate section of the retractor, which is preferably made of a metal or alloy, has a first elongate proximal end portion, a first elongate distal end portion, a first elongate outer surface, and a first elongate inner surface, and functions to transfer lifting and/or insertion forces from the handle member to the skin bridge of the patient.
In an exemplary aspect of the present invention, at least a portion of the first elongate section preferably is non-linear. Preferably, this non-linear area is either curved or bent, and spans at least the area between the first elongate proximal end portion and the first elongate distal end portion.
The second elongate section, which is preferably made of a semi-rigid material that is substantially transparent, has a second elongate proximal end portion, a second elongate distal end portion, a second elongate outer surface and a second elongate inner surface, and functions to perform the illumination feature of the present invention.
The second elongate section is either substantially straight (e.g., when the first elongate section is curved) or bent (e.g., when the first elongate section is bent), and is preferably slidable laterally with respect to a portion of the first elongate section and into engagement with the first elongate section such that the first and second elongate sections are substantially adjacent to each other while engaged.
As used herein, reference to the proximal end portion of an element is intended to denote the end portion of an element that is spaced apart from the handle member, and reference to the distal end portion of an element is intended to denote the end portion of an element that is generally adjacent to or closer to the handle member of the present invention.
The first elongate proximal end portion of the first elongate section preferably has a rounded shape or a smoothly radiused pointed shape that allows the retractor to be pushed into any of the transverse incisions. Once so inserted, the retractor can be safely pushed forward underneath the skin, and into/within the deep fascia.
Additionally, the first elongate proximal end portion of the first elongate section preferably includes an insertion area to receive and retain the proximal end portion of the second elongate section, and to ensure that these portions remain adjacent to each other during the harvesting procedure. In a preferred aspect of the invention, the insertion area is a substantially U-shaped flap or loop into which the proximal end portion of the second elongate section is laterally, securely insertable.
Although the insertion area should protrude from the first elongate section enough to allow for insertion of the second elongate section therein, it also should provide a low profile extension that does not deter dissection of the tissue, and that ensures that the inserted second elongate section will not become dislodged therefrom during the harvesting procedure.
The proximal end portion of the second elongate section preferably has a rounded shape or, alternatively, a smoothly radiused pointed shape. The shape of the second elongate section proximal end portion is selected to allow for insertion thereof into the insertion area of the first elongate section. Its shape also should ensure that the proximal end portion of the retractor, when the first and second elongate sections are connected, can readily penetrate tissue as the retractor is inserted into a small incision and maneuvered into position, and that the proximal end portion of the second elongate section will be securely retained in the insertion area.
Moreover, the proximal end portion of the second elongate section also is preferably configured/shaped to direct light forwardly of the retractor (in addition to the light that emanates from, and extends the substantial length of the retractor) during use to allow for improved visualization of the subcutaneous space in connection with the harvesting procedure.
The retractor of the present invention also preferably includes a bent dissecting tip, which extends from the first elongate section at the proximal end portion of the first elongate section. This tip allows medical personnel to use the retractor as a dissecting device while the retractor is being maneuvered into, around and/or through the connective tissue and muscle surrounding the radial artery. The tip may include serrations thereupon to assist in the dissection of the tissue, and in retaining the retractor in its desired position during the harvesting procedure.
In order to enhance the reflective qualities of the illuminated retractor, the first elongate inner surface of the first elongate section may include a mirrored surface thereon. Also, the second elongate inner surface of the second elongate section may have a machined or molded (e.g., injection molded) micro-lens surface thereon that refracts light forwardly at a desired angle.
In an alternate aspect of the invention, the second elongate section may have a graded dot screen surface. The mirrored surface of the first elongate inner surface, and the machined surface of the second elongate inner surface function to minimize the light intensity loss of the light energy that is provided to the surgical field by the illuminated retractor.
In yet another alternate aspect of the invention, the second elongate inner surface may be reflective, in order to direct illumination outwardly from the second elongate outer surface. Furthermore, the second elongate section may be constructed so as to reflect to the illumination forwardly from the second elongate section to illuminate the skin bridge forwardly of the illuminated surgical retractor.
For example, the second elongate section may be formed so that the light is transmitted at a forward angle that is preferably between about 15xc2x0 and 75xc2x0, and, more preferably, between about 30xc2x0 and 60xc2x0 relative to the second elongate section, and so that illumination may be scattered to the sides of the retractor as desired.
A preferred form of the retractor also includes a connector, preferably a twist type connector, between the handle member and the first and second elongate sections. This allows for a simple connection (e.g., a one-quarter turn) to reversibly but assuredly secure the first elongate section to the handle with confidence that these components will remain attached as the skin bridge is defined/created and maintained.
The connector also connects the handle member to the second elongate section to ensure that the light energy travels from the light source, through the handle member, and into the second elongate section. The light energy fills the second elongate section such that light energy is radiated from the second elongate section into the subcutaneous space defined by the retractor.
In this manner, light can be provided from the light source via the optical cable to the illumination input end portion of the second elongate section so that the second elongate section is illuminated, thus resulting in an illuminated surgical field.
A further feature of a preferred form of the present invention is that the distal end portion (or heel portion) of the illuminated retractor is formed to shield all nearby medical personnel from the light created by the distal end portion of the second elongate section. Additionally, the first elongate section may include a side channel in a shaft portion thereof to allow a shaft shaped portion of the second elongate section to be inserted therethrough, thus allowing the second elongate section to be replaceably mounted onto the first elongate section as desired.
A further feature of the illuminated retractor of the present invention is that at least a portion of the shaft shaped portion and/or the distal end portion of the second elongate section is preferably spaced apart from at least a portion of the shaft portion and/or the distal end portion of the first elongate section to ensure that there is no heat buildup between these elements of the retractor.
Still other features of a preferred form of the retractor of the present invention are that the light cable passes through the handle member of the retractor, and that a portion of the handle member may be formed to allow the light generated by the light cable to be observed through the body of the handle member. These features enable medical personnel using the retractor to readily determine whether or not the light source for the retractor is in operation.
Additionally, in a further preferred aspect of the invention, the retractor may include a second connection that may be used to connect a standard light cable at the top of the handle member to a shortened light cable in the handle member of the retractor, so that the handle member and elongate members may be packaged and/or sterilized separately. Alternately, the light cable may be allowed to pass through the handle member for direct connection to the light source and the second elongate member as desired.
Still other aspects, embodiments and advantages of the present invention are discussed in detail below.